1. Field of the Invention
This invention relates generally to medical devices for topical photodynamic therapy (PDT) treatment of patients, and particularly to a flexible and conforming pad or a shaped-article containing light-emitting elements which is placed in contact with the patient""s skin or tissue, and a method for making that apparatus.
2. Technical Background
The field of topical photodynamic therapy (PDT) and medical devices for practicing photodynamic therapy are known. In one approach, various types of pads, patches, or garments containing light-emitting elements (or having light-emitting elements attached thereto) are placed in contact with the skin or other tissue of the patient to irradiate that portion of the skin or tissue with light. The light may itself provide a therapeutic benefit due to its characteristic wavelengths, or may act in combination with a pharmacological agent (which is applied topically to the patient""s skin or tissue, or is injected or ingested by the patient) which reacts with the light and produces a therapeutic benefit. The pharmacological agent may accumulate in the region being treated, or may react upon exposure to the light at the exposed region while traversing within the circulatory system.
Representative examples of pads, patches, garments, or shaped objects which contain or carry light-emitting elements for use in photodynamic therapy are known.
One approach is to provide a flexible xe2x80x9ccircuit boardxe2x80x9d containing an array or network of diode lasers or LEDs bonded to a silicon pad and encased by a clear, co-molded silicone cover which serves as a lens for the light-emitting elements. One specific type of light-emitting element proposed for the array is a vertical-cavity surface-emitting laser (VCSEL) that is wavelength-specific for PDT or immunotherapy. Such an array of light-emitting elements within the silicon cover may be shaped to conform to certain regions of the patient""s body, such as a glove or sock for the patient""s hand or foot, a band which may be wrapped around an extremity such as an arm or leg, garments which may cover a large portion of the patient""s torso or trunk, as well as strips or patches designed to access substantially remote or partially-internal areas such as the gums within the patient""s mouth. In some applications, the pads may be adhered to the patient""s skin or other tissue using an adhesive.
Other approaches permit internal or more invasive uses of flexible light-emitting pads or patches for photodynamic therapy via conventional surgery or laparoscopy, with representative examples of treatment sites being a region of the pericardium or heart muscle, around or within an artery or arterial stenosis, or adjacent to or within an organ or tumor.
The invention is a photodynamic therapy (PDT) treatment device for delivering light from one or more light-emitting elements which is flexible or sufficiently pliable to conform to the skin or tissue of the patient, and which provides a skin-adhering surface which adheres directly to the patient""s skin or tissue upon contact, will automatically peel from the skin (or itself) if wrapped or stretched too tightly, and may be selectively removed, washed, and repositioned as desired.
In one embodiment, the light-emitting treatment device is a flexible, surface-conforming pad or covering including a flexible polymeric shell having an area to receive the light-emitting elements, the shell being at least partially filled or covered with a flexible filler or liner material such as a cured gel which retains a skin-adhering quality after curing, with the shell and liner material providing an exposed skin-adhering surface positioned generally between the light-emitting elements and the patient""s skin. In an alternate embodiment, the light-emitting treatment device is similarly fashioned as a generally rigid yet sufficiently pliable surface-conforming shaped-article.
The invention further includes a method for making the light-emitting treatment device having a skin-adhering surface which enhances manufacturability by permitting multiple light-emitting elements and circuitry to be laid out without subsequent disturbance, embedded at or slightly above room temperature without being subjected to a molding process, substantially surrounded and secured to maintain alignment and maximize heat dissipation, and providing more uniform and reproducible light transmission or diffusion properties compared with the slippage, gaps, and irregularities that may could occur when layering the light-emitting elements between pre-molded silicone sheets as taught in the prior art.
In one embodiment, the method includes providing a molded polymeric or flexible polymeric shell member defining an area for receiving the light-emitting elements, positioning the light-emitting elements on or within the shell member, at least partially filling the shell member or partially covering the light-emitting elements with a gel liner material in a viscous liquid state, and curing the liner material to provide a flexible pad or shaped-article which maintains a skin-adhering surface which may be applied to a region of the patient""s skin or tissue such that the light-emitting elements irradiate that region.
In summary, the invention relates to a light-emitting medical treatment device including a shell member and a liner (or filler) material defining a surface which is skin-adhering. The shell member, liner material, and light-emitting elements form an assembly configured to emit energy for photodynamic therapy onto a body surface. The treatment device may be either substantially flexible or sufficiently rigid to hold a predetermined shape (yet sufficiently pliable so as to be applied to the patient""s body), and may be fabricated to conform to any selected body surface or to a predetermined body shape. The shell member and liner material may be made of compatible polymeric materials, such as a molded silicone rubber shell member and silicone gel liner material. The shell member and liner material may be configured in a substantially integral and unitary structure, and may form a light-diffusing and heat-dissipating covering for the light-emitting elements. The light-emitting elements may be laser diodes, LEDs, optical fibers, or any other suitable source of therapeutic light.
The invention also relates to a product made from the process or method of this invention.
Still other representative embodiments and advantages of the present invention and methods of construction of the same will become readily apparent to those skilled in the art from the following detailed description, wherein only the preferred embodiments are shown and described, simply by way of illustration of the best mode contemplated for carrying out the invention. As will be realized, the invention is capable of other and different embodiments and methods of construction, and its several details are capable of modification or adaptation in various respects all without departing from the invention as disclosed and claimed. Accordingly, the appended drawings and description contained herein, as well as the descriptions and drawings contained in the applications and associated documents to which the benefit of priority has been claimed and which are incorporated herein by reference as though fully set forth, are to be regarded as illustrative in nature and not as restrictive or limiting.